Make a simple 'dirt' track in Trackmania NationsAdvanced mode only track editing/creation. This video shows how to layout a basic 'dirt' track and how some of the core components for them fit together (note that this is *not* a race-able track, it just shows the basics of placing the sections together).
ALT+[
LMB/MMB/RMB] to pan/zoom/rotate editor screen.
MMB to raise/lower height of dirt track base unit.